This invention relates to a fuel injection system for supplying fuel to an internal combustion engine of an automobile, and more particularly to a fuel injection system having a fuel cut mechanism for stopping fuel injection from an injector at idle operation in response to engine temperature and engine speed.
In a conventional fuel cut mechanism, an idle switch for detecting idling condition is fixed to the body of a fuel injection system and is adapted to detect only a fully closed position of the throttle valve after warm-up operation of the engine. In other words, it cannot detect the idling condition except the fully closed position of the throttle valve, that is, the fast idle condition wherein the throttle valve is slightly opened during periods from cold engine starting to engine warm-up completion. Accordingly, in order to detect such a fast idle condition, it is necessary to provide another sensor, thus rendering the structure and the control of the mechanism to be complicated.